Why do people call them ponies?

[Aeliott]

When they are clearly fully mature, adult horses! I mean maybe on Lalafells because they're tiny, but they still have fully developed horns. These mean-looking beasts of elemental burden don't look like they'd take too kindly being referred to as a cute and endearing name (especially Nightmare!). Why ponies and why is it so universally accepted? :P

[Saziel]

Honestly, I hate the term lol.

[Ultimatecalibur]

The main reason is its a memetic reference to another source of brightly colored equines.

[kyuven]

The main reason is its a memetic reference to another source of brightly colored equines.

This. I mean, come on. They're too cute to be "horses"
"Horse" implies majesty. "Ponies" are cute.

[MilesSaintboroguh]

I just call them skittles.

[SecretCrowds]

Here you go.

[Shai]

A pony isn't a baby horse. You can have a full, adult, mature pony.

[Kidblinks]

It sounds more cute.

[Elim]

Because it's funny to call them ponies.

my little pony picture

Here you go.

Also this.

[Quesse]

Let's be honest, most of them do look like this with all the ridiculous sparkles flying around. Ponies fits the best.

Here you go.